Missing buttons.

I don’t know if because I’m new to this I’m missing something completely obvious (I hope I’m not wasting anyone’s time!), but I’m completely frustrated. No where under my presentation button are there any buttons for sidebar widgets or headers…. The only two buttons are for ‘Themes’ & ‘Theme Editor’. The book I purchased (WordPress 2) claims these buttons should appear. Please tell me what this beginner is missing, & I will be so gratfeul.